Electronic and optoelectronic materials and devices inspired by nature

Abstract

Inorganic semiconductors permeate virtually every sphere of modern human existence. Micro-fabricated memory elements, processors, sensors, circuit elements, lasers, displays, detectors, etc are ubiquitous. However, the dawn of the 21st century has brought with it immense new challenges, and indeed opportunities-some of which require a paradigm shift in the way we think about resource use and disposal, which in turn directly impacts our ongoing relationship with inorganic semiconductors such as silicon and gallium arsenide. Furthermore, advances in fields such as nano-medicine and bioelectronics, and the impending revolution of the 'ubiquitous sensor network', all require new functional materials which are bio-compatible, cheap, have minimal embedded manufacturing energy plus extremely low power consumption, and are mechanically robust and flexible for integration with tissues, building structures, fabrics and all manner of hosts. In this short review article we summarize current progress in creating materials with such properties. We focus primarily on organic and bio-organic electronic and optoelectronic systems derived from or inspired by nature, and outline the complex charge transport and photo-physics which control their behaviour. We also introduce the concept of electrical devices based upon ion or proton flow ('ionics and protonics') and focus particularly on their role as a signal interface with biological systems. Finally, we highlight recent advances in creating working devices, some of which have bio-inspired architectures, and summarize the current issues, challenges and potential solutions. This is a rich new playground for the modern materials physicist.

Protonic transistors from thin reflectin films

“…[1][2][3][4][5][6][7][8][9] Indeed, the processing and fabrication techniques required for the preparation of these transistors are simple, convenient, and inexpensive. [1][2][3][4][5] The constituent organic or biological materials are also amenable to chemical modification and functionalization. 1,[5][6][7] In addition, the mechanical properties of organic materials are inherently compatible with those of biological systems.…”

“…1,[5][6][7] In addition, the mechanical properties of organic materials are inherently compatible with those of biological systems. 1,3,8 Moreover, organic and biological ionic conductors are well suited for the transduction of biochemical events into electronic signals. 1,[4][5][6][7]9 These key advantages have made ionic transistors from organic and biological materials exciting targets for further research and development.…”

Toward biomaterial-based implantable photonic devices

“…Bio-OLEDs could also be integrated with biomaterials-based electronics to create multifunctional implantable optoelectronic devices. Biocompatible electronics [194,195] are a much larger and more developed research area than biocompatible photonics. For example, completely biodegradable transistors [196,197] and other electronic components [22] have been developed.…”

Natural melanin pigments and their interfaces with metal ions and oxides: emerging concepts and technologies

“…Electrical response of eumelanin: amorphous semiconductor model, mixed ionic-electronic conduction, electrochemical interfacial processes, and energy storage Biologic materials, such as proteins, peptides, and melanin, occur naturally in hydrated environments, such that their electrical response includes an important contribution from waterassisted proton transport. [31][32][33][34] The electrical properties of eumelanin have fascinated scientists since the late 1960s. After the observation of a reversible resistive switching in eumelanin pellets reported in 1974 by McGinness et al, [35] the amorphous semiconductor model was adopted to explain the strong hydration dependence of the conductivity.…”